After the overnight arrests of four Nepal Maoists in Howrah station, the police on Thursday cracked down on those in the city suspected to have connections with the Maoist militants. Ten more Nepali youths from the city and its suburbs were detained, on the basis of information provided by the arrested quartet.

Police claimed the arrested and detained men revealed details of “recruitment of youths and motivation and training programmes’’ for militant activity in Nepal that were conducted in and around Calcutta for the past year.

Sources said police raided houses in Tiljala, Barasat, Hooghly and several other areas during the day and seized several documents detailing activities of the group in the city and its contacts in the city, the suburbs and in Nepal.

Additional director-general of police, railways, S.C. Awasthy, confirmed the arrests and detention of Nepal Maoists during the day, but refused to divulge details, citing “international ramifications”. “Officers of the intelligence branch (IB) are interrogating the Maoists. More raids are being conducted and youths detained. I can’t give out any more information now,’’ he said.

Later on Thursday, police said they had sealed four houses in and around the city where the Maoists conducted “motivation classes for new recruits’’. Maoist literature was seized from the houses.

The police identified the four Maoists arrested at Howrah station late on Wednesday as Harish Giri, Nayan Singh, Balbahadur Beka and Bhim Bahadur Beka. “We had information that the four youths would come to the station. So, we intercepted and arrested them,” said superintendent of police, Howrah GRP, Debashis Roy.

IB officials said a search of the youths yielded documents “urging people to take up arms against the Nepalese government’’.

Investigations also revealed that Harish Giri, of Tiljala, was the local contact of the Maoist guerrillas and one of the chief organisers of the underground outfit in Calcutta. Originally from Biratnagar, in Nepal, Giri had arrived in Calcutta about 10 years ago and put up in different places before renting an apartment in Tiljala recently. He was staying with his wife and working as a waiter in a local restaurant.

All the while he was in Calcutta, Giri maintained contact with his acquaintances in Nepal. About a year ago, three of his acquaintances — Bal Bahadur, Bhim Bahadur and Nayan Singh — decided to join him in the city.

An officer who interrogated the youths said Giri and the trio would contact Nepali youths settled in the city and suburbs and convince them to join their “armed struggle” in Nepal. “They targeted mainly students and unemployed youths,’’ an officer said.

Apart from Giri and his acquaintances, the youths detained on Thursday told the police that they had recruited 30 Nepali youths in the past six months and after four weeks of “classes in motivation” and a week of extensive physical training, the youths were sent to Nepal through Birgunj, on the Nepal-Bihar border. However, none of the recruited youths were given training in arms.

The Nepalese consulate in the city reacted with caution on Thursday. Consul-general Yuba Raj Bhusal told Metro that the Indian security agencies had not informed his office of “details of the arrests”. “I have asked my office to get in touch with the authorities to get more information,’’ he added.

Bhusal said Calcutta was never a hotbed of Maoist guerrillas. “Our information reveals that Maoists are taking shelter closer to the Indo-Nepalese border, but the arrests are news to us. I will take it up through the proper diplomatic channel,’’ he said.